氮肥用量对油菜产量及氮素利用效率的影响

通过大田试验研究氮肥用量对油菜产量、养分含量、养分累积量及氮肥利用效率的影响。结果表明,与不施氮相比,施氮肥75、150和225kg/hm2平均分别增产41.9%、70.3%和66.2%,籽粒含氮量分别提高9.1%、14.2%和13.1%,植株地上部氮素总累积量分别增加59.6%、111.6%和108.0%。施氮促进油菜生长发育,显著提高油菜对氮素的吸收、累积和籽粒需氮量,但氮肥农学利用率、偏生产力和表观利用率均随氮肥用量的增加显著下降。氮肥用量在150kg/hm2时,能较好地协调油菜高产与氮肥合理利用的统一。

Effect of nitrogen application rate on yield and nitrogen fertilization efficiency in rapeseed

Field experiments were carried out to study the effects of nitrogen（N） application rate on rapeseed yield and N fertilizer use efficiency in Hubei Province during 2007 to 2008.Compared to no N application,the yield of N treatments（as 75,150 and 225kg/hm2） increased 41.9%,70.3% and 66.2% respectively.N content increased 9.1%,14.2% and 13.1%,and total N absorbed by above ground parts increased 59.6%,111.6% and 108.0% respectively.The results demonstrated that N application significant promoted growth,yield and N accumulation.With increased N application rate,N requirement for 100kg-seeds was increased,while N agronomic use efficiency（AUE）,partial factor productivity（PFP） and apparent recovery efficiency（ARE） of rapeseed decreased significantly.Based on rapeseed yield and N use efficiency,the optimum N fertilizer application rate was 150kg/hm2 in Hubei Province.